程序允许用户选择图片，然后选择要制作的图片数量。目标（稍后）是在每件作品下面都有数学问题。因此，如果他们选择4个问题，那么图片将被分成4个部分，每个部分下面将是一个数学问题（当然总共4个）。我的问题是：我如何才能实现这一目标？我已经读过我需要一个鼠标监听器，但是我不确定这是否是正确的方法，在这种情况下我不太确定如何使用它们。
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ButtonGroup;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.KeyStroke;
public class Menu extends JFrame {
JMenuBar menuBar;
ButtonGroup pictureGroup, problemsGroup;
BufferedImage picture1img, picture2img, picture3img;
JMenu choiceOfThreePictures, numberOfProblems;
JRadioButtonMenuItem picture1, picture2, picture3, fourProblems, nineProblems, sixteenProblems;
private String picture1Address = "/Users/Administrator/Dropbox/Java/HW6Wilson/HW6Wilson/Picture1.jpg";
private String picture2Address = "/Users/Administrator/Dropbox/Java/HW6Wilson/HW6Wilson/Picture2.jpg";
private String picture3Address = "/Users/Administrator/Dropbox/Java/HW6Wilson/HW6Wilson/Picture3.jpg";
KeyStroke picture1HotKey, picture2HotKey, picture3HotKey, fourProblemsHotKey, nineProblemsHotKey, sixteenProblemsHotKey;
public Menu() {
// Create the menu bar.
menuBar = new JMenuBar();
setJMenuBar(menuBar);
// Create Picture choices on Menu Bar and make Mnemonic
choiceOfThreePictures = new JMenu("Picture Choices");
choiceOfThreePictures.setMnemonic(KeyEvent.VK_J);
// Add Picture choices on Menu Bar
menuBar.add(choiceOfThreePictures);
// Create MenuItems onto Picture choices
pictureGroup = new ButtonGroup();
// Create button and accelerator for picture 1
picture1 = new JRadioButtonMenuItem("Picture 1");
picture1HotKey = KeyStroke.getKeyStroke(KeyEvent.VK_1, KeyEvent.CTRL_DOWN_MASK);
picture1.setAccelerator(picture1HotKey);
// Create button and accelerator for picture 2
picture2 = new JRadioButtonMenuItem("Picture 2");
picture2HotKey = KeyStroke.getKeyStroke(KeyEvent.VK_2, KeyEvent.CTRL_DOWN_MASK);
picture2.setAccelerator(picture2HotKey);
// Create button and accelerator for picture 3
picture3 = new JRadioButtonMenuItem("Picture 3");
picture3HotKey = KeyStroke.getKeyStroke(KeyEvent.VK_3, KeyEvent.CTRL_DOWN_MASK);
picture3.setAccelerator(picture3HotKey);
// Add Picture Choices to Picutre choices menu
choiceOfThreePictures.add(picture1);
pictureGroup.add(picture1);
choiceOfThreePictures.add(picture2);
pictureGroup.add(picture2);
choiceOfThreePictures.add(picture3);
pictureGroup.add(picture3);
// Create Number Of Problems on Menu Bar and make Mnemonic
numberOfProblems = new JMenu("Number Of Problems");
numberOfProblems.setMnemonic(KeyEvent.VK_T);
// Add Number Of problems on Menu Bar
menuBar.add(numberOfProblems);
// Create Menu Items onto Number Of problems
problemsGroup = new ButtonGroup();
// Create button and accelerator for fourProblems
fourProblems = new JRadioButtonMenuItem("4");
fourProblemsHotKey = KeyStroke.getKeyStroke(KeyEvent.VK_F4, KeyEvent.CTRL_DOWN_MASK);
fourProblems.setAccelerator(fourProblemsHotKey);
// Create button and accelertor for nineProblems
nineProblems = new JRadioButtonMenuItem("9");
nineProblemsHotKey = KeyStroke.getKeyStroke(KeyEvent.VK_F9, KeyEvent.CTRL_DOWN_MASK);
nineProblems.setAccelerator(nineProblemsHotKey);
// Create button and accelerator for sixteenProblems
sixteenProblems = new JRadioButtonMenuItem("16");
sixteenProblemsHotKey = KeyStroke.getKeyStroke(KeyEvent.VK_F12, KeyEvent.CTRL_DOWN_MASK);
sixteenProblems.setAccelerator(sixteenProblemsHotKey);
// Add Number Of problems onto menu
numberOfProblems.add(fourProblems);
problemsGroup.add(fourProblems);
numberOfProblems.add(nineProblems);
problemsGroup.add(nineProblems);
numberOfProblems.add(sixteenProblems);
problemsGroup.add(sixteenProblems);
// Start creating ActionListeners for pictures
picture1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
System.out.println("Working");
try {
picture1img = ImageIO.read(new File(picture1Address));
getContentPane().removeAll();
getContentPane().add(new JLabel(new ImageIcon(picture1img)));
revalidate();
} catch (IOException e) {
System.out.println("Couldn't find image.");
}
}
});
picture2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
System.out.println("Working");
try {
picture2img = ImageIO.read(new File(picture2Address));
getContentPane().removeAll();
getContentPane().add(new JLabel(new ImageIcon(picture2img)));
revalidate();
} catch (IOException e) {
System.out.println("Couldn't find image.");
}
}
});
picture3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
System.out.println("Working");
try {
picture3img = ImageIO.read(new File(picture3Address));
getContentPane().removeAll();
getContentPane().add(new JLabel(new ImageIcon(picture3img)));
revalidate();
} catch (IOException e) {
System.out.println("Couldn't find image.");
}
}
});
// Create Action Listeners for problems
fourProblems.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0){
if (picture1.isSelected()){
try {
getContentPane().removeAll();
imageSplitter(picture1Address, 2);
revalidate();
} catch (IOException e){
e.printStackTrace();
}
} else if (picture2.isSelected()){
try {
getContentPane().removeAll();
imageSplitter(picture2Address, 2);
revalidate();
} catch (IOException e){
e.printStackTrace();
}
} else if (picture3.isSelected()){
try {
getContentPane().removeAll();
imageSplitter(picture3Address, 2);
revalidate();
} catch (IOException e){
e.printStackTrace();
}
}
}
});
nineProblems.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0){
if (picture1.isSelected()){
try {
getContentPane().removeAll();
imageSplitter(picture1Address, 3);
revalidate();
} catch (IOException e){
e.printStackTrace();
}
} else if (picture2.isSelected()){
try {
getContentPane().removeAll();
imageSplitter(picture2Address, 3);
revalidate();
} catch (IOException e){
e.printStackTrace();
}
} else if (picture3.isSelected()){
try {
getContentPane().removeAll();
imageSplitter(picture3Address, 3);
revalidate();
} catch (IOException e){
e.printStackTrace();
}
}
}
});
sixteenProblems.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0){
if (picture1.isSelected()){
try {
getContentPane().removeAll();
imageSplitter(picture1Address, 4);
revalidate();
} catch (IOException e){
e.printStackTrace();
}
} else if (picture2.isSelected()){
try {
getContentPane().removeAll();
imageSplitter(picture2Address, 4);
revalidate();
} catch (IOException e){
e.printStackTrace();
}
} else if (picture3.isSelected()){
try {
getContentPane().removeAll();
imageSplitter(picture3Address, 4);
revalidate();
} catch (IOException e){
e.printStackTrace();
}
}
}
});
}
// Image Splitter Method
public void imageSplitter(String filename, int rowsandcolumns) throws IOException {
getContentPane().setLayout(new GridLayout(rowsandcolumns, rowsandcolumns));
// reads in file as an image
BufferedImage image = ImageIO.read(new File(filename));
int rows = rowsandcolumns; // You should decide the values for rows and cols
// variables
int columns = rowsandcolumns;
int chunks = rows * columns;
int chunkWidth = image.getWidth() / columns; // determines the chunk
// width and height
int chunkHeight = image.getHeight() / rows;
int count = 0;
// initialize array to store 4 new images
BufferedImage images[] = new BufferedImage[chunks];
// For loop for rows
for (int x = 0; x < rows; x++) {
// For loop for columns
for (int y = 0; y < columns; y++) {
// Creates subimages of the main image and stores them in the
// order of Quadrant II, III, I, IV
images[count] = image.getSubimage((x * chunkWidth), (y * chunkHeight), chunkWidth, chunkHeight);
count++;
}
}
// For Loop that writes the each of the 4 new images from the array.
for (int i = 1; i < images.length + 1; i++) {
// ImageIO.write(images[i - 1], "jpg", new File("image" + i +
// ".jpg"));
getContentPane().add(new JLabel(new ImageIcon(images[i - 1])));
}
}
public static void main(String[] args) {
Menu mb = new Menu();
mb.setSize(900, 700);
mb.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mb.setVisible(true);
}
}
答案 0 :(得分：0)
这是一个类ImageButton，它是一个显示图像部分的按钮，当点击该按钮时它会显示问题。
public class ImageButton extends JButton{
private String problem;
private BufferedImage image;
private Boolean status;//true -> image, false -> problem, null -> answered
public ImageButton(String problem, BufferedImage image, int x, int y, int width, int height){
this.image = image.subImage(x,y,width,height);
this.problem = problem;
this.setFocusPainted(false);
this.setBorderPainted(false);
this.setContentAreaFilled(false);
this.addActionListener(new DefaultListener());
this.status = true;
}
public void action(){
if(status == true){
status = false;
}
}
public void answer(){
if(status == false){
status = null;
}
}
public void paintComponent(Graphics g){
if(status == null){
// TODO what will happen after it is answered
}else{
g.drawImage(image, 0, 0, this);
if(!status){
printString(g, problem, 10);
}
}
}
public static void printString(Graphics g, String string, int height) {
if (string != null) {
int width = g.getFontMetrics().stringWidth(string);
int length = string.length();
if (width > getWidth() - 40) {
length = cutString(g, string);
g.drawString(string.substring(0, length), 20, height);
printString(g, string.substring(length), height + 35);
}
g.drawString(string.substring(0, length), 20, height);
}
}
public static int cutString(Graphics g, String string) {
int count = 1;
int space = 0;
while (g.getFontMetrics().stringWidth(string.substring(0, count)) < getWidth() - 40) {
if (string.charAt(count) == 32) {
space = count;
}
count++;
}
return space;
}
}
以下是ActionListener，我这样做的原因是因为这样更优雅，更容易在将来进行审核和维护。
public class DefaultListener implements ActionListener{
@override
public void actionPerformed(ActionEvent event){
Object source = event.getSource();
if(source instanceof ImageButton){
(ImageButton)source.action();
}
}
}
最后，这是获取图像的方法：
public JPanel getPanel(BufferedImage image, int count){
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, 1));//0 is horizontal, 1 is vertical
int columns = (int)Math.ceil(Math.sqrt(count));
int rows = (int)Math.ceil((double)count / (double)columns);
int imageHeight = image.getHeight();
int imageWidth = image.getWidth();
int buttonWidth = imageWidth / columns;
int buttonHeight = imageHeight / rows;
int index = 0;
for(int row = 0; row < rows; row++){
JPanel smallPanel = new JPanel();
smallPanel.setLayout(new BoxLayout(panel, 0));
for(int column = 0; column < columns; column++){
if(index >= count){
break;
}
int x = buttonWidth * column;
int y = buttonHeight * row;
int width = buttonWidth;
int height = buttonHeight;
ImageButton button = new ImageButton(--Insert Problem--,image, x,y,width,height);
smallPanel.add(button);
}
panel.add(smallPanel);
index++;
}
return panel;
}